Natural cellulosic feedstocks are typically referred to as “biomass”. Many types of biomass, including wood, paper, agricultural residues, herbaceous crops, and lignocellulosic municipal and industrial solid wastes have been considered as feedstocks for the production and preparation of a wide range of goods. Plant biomass materials are comprised primarily of cellulose, hemicellulose, other sugars, and lignin, bound together in a complex gel-like structure along with amounts of extractives, pectins, proteins and ash. Thus, successful commercial use of biomass as a feedstock or its components directly may depend on the separation of the various constituents.
Many steps are often required in production, harvesting, storage, transporting, and processing of biomass to yield useful products. One step in the processing is the separation, or fractionation, of biomass into its major components: extractives, hemicellulose, lignin, other sugars, and cellulose. Many approaches have been investigated for disentangling this complex structure. Once this separation has been achieved, a variety of paths are opened for further processing of each component into marketable products. For example, the possibility of producing products such as biofuels, polymers and latex replacements from biomass has recently received much attention. This attention is due to the availability of large amounts of cellulosic feedstock, the need to reduce burning or landfilling of waste cellulosic materials, and the usefulness of sugar and cellulose as raw materials substituting for oil-based products. Other biomass constituents, such as isolated extractives and lignins from the biomass, may also have potential market value.
The difficulty is efficiently and in an environmentally friendly manner separating the components from each other. Thus there continues to be a need for improved systems and methods for separating solid biomass into its constituent components that take into consideration factors such as environmental and energy concerns, efficiency and cost-effectiveness.